The phase equilibria in the quasi-binary Cu2GeS3/Se3/-CdS/Se/-systems

The phase diagram of the quasi-binary Cu2GeS3-CdS, Cu2GeSe3-CdSe and Cu2Se-GeSe2 systems was studied by DTA, X-ray diffraction, and microstructural methods. Four quaternary phases are observed in the quasi-binary Cu2GeS3/Se-3 /-CdS/Se/ system: Cu2CdGeS4, Cu2Cd3GeS6, Cu2CdGeSe4, and Cu2Cd3GeSe6 which melt a incongruently melting at 1282, 1329, 1103, and 1173 K, respectively. Cu2CdGeS4 and Cu2CdGeSe4 crystallize in an orthorhombic structure (space group Pmn2(1), a = 0.7703(1), b = 0.65549(9), c = 0.6312(1) nm) and a tetragonal structure (space group 1(4) over bar 2 m, a = 0.57489(5), c = 1.1955(1)), respectively. The quasi-binary Cu2Se-GeSe2 system was studied in the region 15-60 mol.% GeSe2. Cu2GeSe3 melts congruently at 1053 K and crystallizes in an orthorhombic structure (space group Imm2, a = 1.1857(1), b = 0.39522(8), c = 0.54865(7) nm) (C) 2000 Elsevier Science S.A. All rights reserved.